But a "restaurant on wheels" is a idea that will be truly profitable, at least in theory! Its true that restaurants abound in localities today but mobility of people (and their eating preferences) from one location to another has also increased. Restaurants which are profitable today may not be tomorrow. A restaurant on wheels can easily adapt to changing demands by constantly moving on from low demand areas to high demand ones. Maybe, Amazon can even build an AI or something to guide it for most efficiency.